Hides empty groups, shows non empty groups

<div class="definition">
    updateEmptyGroups()
</div>

Returns <i>undefined</i>.

<h4>Description</h4>

This method will hide all groups that have all fields hidden and show all groups that have visible fields. It is used internally when you show/hide fields. You can also call it to update empty groups.
<div style="height: 10px"></div>

If you have following form:
<textarea class="javascript">
let form = new w2form({
    name     : 'form',
    formURL : '/server/path',
    fields: [
        { field: 'first_name', type: 'text', required: true, html: { group: 'General' } },
        { field: 'last_name', type: 'text', required: true },
        { field: 'email', type: 'email' }
    ],
    actions: {
        "save": function (target, data) { this.validate(); },
        "reset": function (target, data) { this.clear(); }
    }
})
</textarea>

You can do:
<textarea class="javascript">
w2ui.form.updateEmptyGroups()
</textarea>